hokanson



Nov. 11 1924. 1,515,438

0. HOKANSON RIBBON MECHANISM FOR TYPEWRITERS Filed Sent. l3 1920 aShuts-Shut 1 izz/57274;;

NOV.

O. A. HOKANSON RIBBON MECHANISM FOR TYPEWRITERS Filed Sent. 13. 1920' 3Shuts-Sheet. 2

I'll! ILI IaLI l l I l l I I II llllllllll NOV. 11 1924.

. O. A. HOKANSON RIBBON MECHANISM FOR TYPEWRITERS Filed Sept. 13. '19203 Shuts-Shoot 3 Patented Nov. 11, 1924.

UNITED STATES PATENT OFFICE.

OTTO A. HOKANSON, O1" WOODSTOCK, ILLINOIS, ASSIGNOR TO WOODSTOCK TYPE-WRITER COMPANY, OF WOODSTOCK, ILLINOIS, A CORPORATION OF ILLINOIS.

RIBBON MECHANISM FOR TYPEWRITERS.

Application filed September 13, 1920. Serial No. 410,044.

To all whom it may concern:

Be it known that I, 'r'ro A. HoKANsoN, a citizen of the United States,residing at \Noodstock in the county of McHenry and State of Illinois.have invented certain new and useful Improvements in Ribbon Mechanismfor Typewriters, of which the following is a specification.

This invention relates to typewriting machines and more specifically tomechanism for holding and controlling the ribbons for typewriters, andhas for its object the provision of machines of the class named whichshall be of improved construction and operation.

The invention is exemplified in the combination and arrangement of partsshown in the accompanying drawings and described in the followingspecification, and it is more particularly pointed out in the appendedclaims.

In the drawings- Fig. 1 is a vertical section of a portion oi" atypewriter with parts in elevation illustrating one embodiment of theinvention;

Fig. 2 is a horizontal section showing the operating mechanism for aribbon spool at one side of the typewriter;

Fig. 3 illustrates the corresponding mechanism at the opposite side ofthe typewriter from that shown in Fig. 2;

Fig. 4 is a vertical section through the ribbon spool and associatedparts; and

Fig. 5 is a fragmentary view with parts in section showing portions ofthe ribbonfeeding mechanism.

Although the present invention is applicable to various forms oftypewriters, it is illustrated in connection with a typewriter having aframe in which the platen carriage is mounted for movement into and outof operative position to permit the typewriter to be folded into compactform.

A base frame is provided with a pair of arms 11 pivotally mounted at 12on opposite sides of the frame 10. A platen carriage frame 13 is securedto the ends of the arms 11 and is provided with a platen carriage 14arranged to travel thereon. A platen 15 is journaled on the carriage 14.to move therewith. Each of the arms 11 has a flange 16 formed thereon towhich a bracket 17 is secured, the bracket 17 being provided with alower arm 18 and an upper arm 19, as shown best in Figs. 3 and 4. Aribbon spool shaft or spindle 20 is journaled in the arms 18 and 19 andis provided with a ratchet wheel :21 and a collar 22 at its lower end,both rigidly secured to the shaft 20. A collar 23 is "fastened to theshaft 20 above the bracket arm 19 by means of a set screw or otherholding device, and a pin 2% projects upwardly from the upper face ofthe collar 23 in position to engage an opening 25 in a detachable ribbonspool core 26. The core 26 is preferably made of wood and fits over theend of the spindle 20 above the collar 23. A knurled head 27 is providedwith a screw 28 having threaded engagement with an opening 29 formed inthe upper end of the spindle 20. A cover disc 30 is mounted on the screw28 adiacent the lower ,face of the head 27 and although tree to rotateon the screw as a pivot it is held from displacement by a shoulderprovided by the edge of a peripheral groove in the screw in which thedisc 30 is held. A number of points 31 are formed on the lower face ofthe disc 30 so that when a core 26 with the ribbon wound thereon hasbeen slid over the upper end of the spindle 2O the head 27 may bethreaded into the opening 29 so as to press the points 31 into the endoi the core 26 while the disc 30 and core 26 remain stationary relativeto one another. A housing 32 is secured to the upper bracket arm 19 toenclose the ribbon and the disc 30 forms a cover plate above the housingwhen the ribbon is in place. Rotation of the ribbon spool is produced bythe ratchet wheel 21 which is operated by mechanism to be described.

As will be seen from Fig. l the bracket 17 is inclined at an obliqueangle to the arm 11 so that the spindle 20 is inclined to the verticalwhen the arms 11 are in operating position. This makes it possible tomount the ribbon spools and their housings somewhat below the horizontallevel oi the axis of the platen 1:3 and yet support the ribbon so thatits surface will be tan gent to the surface of the platen.

A detent pawl 33 is provided with a pair of ears 34 and 35 pivoted on astud 36 extending downwardly from the upper flange of the arm 11. Theears 34 and 35 with the end of the pawl 33 constitute a yoke which formsa guide for an operating pawl 37 which extends between the ears 3% and35 and between the pawl 33 and its pivot 36. The ends of the pawls 33and 37 are bent inwardly and beveled, as shown in Fig.2, so as to engagethe teeth on the ratchet wheel 21. The rear end of the pawl 37 ispivotally mounted at on a lever A. lug 40 is formed on the ear 3% of thepawl 33 and a similar lug 41 is formed rigidly with the pawl 37 near thepivot 33. The lugs 40 and 41 are connected by a spring 42 which tendsnormally to throw both pawls 33 and 37 into contact with the ratchetwheel 21., The lever 39 is pivoted 43 on a bar M which extends acrossthe chine from one side to the other thereof. The movement of the lever39 about its pivot 43 is limited by a pin 4 5 which extends into anopening 46 in the lever 39. The end 47 of the lever 39 is arrangedadjacent the upper end of a universal member 4'8. The universal member13 extends upwardly from the base frame 1) and is vibrated at eachoperation of the typewriter keys in any wellknown manner. When the partsare in the position shown in Fig. 2 vibration of the universal member 43toward the front of the machine brings the member into enegagment withthe end 47 of the lever 39 and moves the lever about its pivot 3 so asto retract the operating pawl 37. This will shift the pawl. 37backwardly an amount sufficient to engage a notch on the ratchet wheel21, and when the universal member 48 is released the spring 42 willreturn thepawl 37 to its forward position, thus advancing the ratchetwheel 21 a space corresponding to, one tooth on the ratchet wheel. Thisfeeding operation of the typewriter ribbon will take place at eachoperation of a typewriter key until the ribbon has been entirely unwoundfrom the spool :it the opposite side of the typewriter. The position ofthe mechanism for controllii the spool from which the ribbon is beingruiwound is shown in 3. The bar being shifted to the left retains thepivotal support 38 for the inactive pawl 37 in position to swing theforward end of the pawl 37, about the pivot stud 35 so that the end ofthe pawl is disengaged from the "atchet wheel 21 and caused to bearagainst the inner face of the pawl 33 so that both pawls are held out ofmesh with the teeth of the ratchet wheel. This leaves the ratchet wheeland ribbon spool at the right-hand side of the typewriter, as viewed inFigs. 2 and 3, free to rotate as the ribbon is withdrawn therefrom.

For the purpose of reversing the direction of operation of the ribbonspools when the ribbon has been completely unwound from one of thespools a yoke 49 is pivotally mounted on a rod 50 carried by the ends ofthe bracket arms 18 and 19. The yoke 49 is provided with an upper arm 51as shown in Figs. 1 and 3, having an upwardly extending finger 52provided with a slot 53 through which the ribbon passes as it is unwoundfrom the core 26. The ribbon is shown in broken lines in Fig. 3, andadjacent its end is provided with a stop or thickened portion 54 whichis of greater thickness than the width of the slot When the stop engagesthe slot 53 the arm will be swung about its pivotal axis 50 which willcause the lower arm 55 of the yoke 49 to swing in the same direction asthe upper arm 51. A coil spring 56 is secured to the arms 19 and 51 andnormally draws the bracket arms 51 and 5." toward the ribbon spool.During the time that the ribbon is being unwound from the right-- handspool the arm 55 engages a lug 57 on a lever 58 pivoted at 59 on one arm60 of a bell crank pivotally mounted at 615 on a bracket 62 secured tothe platen carriage 'i'rauim as shown in Fig. A spring 63 ly holds thelug 57 against the arm I so that the arm forms a stop to hold the lever58 from rotation about its pivot 59. W hen the arm 55 is movedto theleft, as viewed in Fig. 3, by the ribbon at the manner previouslydescribech the spring 63 will draw the rear end of the lever to theright. as viewed in that figure, bringing it into the path of movementof the universal member 64 corresponding'to the universal member 428 atthe opposite side of the typewriter. As soon as this occurs the nextoperation of the typewriter will cause the universal member 64ltoengagethe end of the lever 58 and force the lever forwardly carrying withitthe arm 60 of the bell. crank pivoted at 61. This bell crank isprovided with a rearwardly extending arm 65 having a slot 66 formed inthe end tl reof .in position to engage a piir 67 carried by the bar 44.One of the bell crank arms 6.3. as shown in Fig. 9.. is provided at itsend with a roller 68 for engaging notches 69 and 70 in a detent. Thedetent 71 is pivoted at 72 on the platen carriage frame 13 and isprovided with a spring 73 for holding it in contact with the roller 68.dhen the arm 65 is moved about its pivot by the lever 58 and universalmember 64, tile roller 68 will be shifted from the notch 69' to thenotch 70, and the bar 4 L will be correspondingly shifted to the rightfrom the position shown in the drawings. This movement of the bar 44will permit the pawls 33 and 37 in Fig. 3 to come into engagement withtheir ratchet wheel.

The entire reversing operation takes place at a single stroke of atypewriter key so that there is no period during which the rib honremains stationary a suiiicient length of time to permit repeated blowsot ti 2 type at one spot. The same movement of the bar Thit will bringthe end 47 ot the lever 39 in Fig. 3 into the path of the universalmember 64 so that further ope ation of the type writer will rotate thespool in Fig. 3 to rewind the ribbon thereon and to withdraw it trom thespool at the opposite end of the typewriter. When the ribbon has beenentirely withdrawn from the opposite spool the ratchet mechanism willagain be reversed and thus the ribbon-feeding mechanism will beautomatically reversed as often as the ribbon is shifted from one spoolto the other.

It will be seen that the ribbon spool holdcrs are mounted on thesupporting arms for the platen carriage frame so that the ribbon holdersare always in proper position relati ve to the platen whether the frameis tolded or in its operating position. The mechanism for feeding theribbon is also carried by the platen carriage frame and the arms bywhich the frame is supported so that its operative relation is notdisturbed by the movement 01"? the platen carriage in folding. Theuniversal members 48 and 64 are locatesil so that they are automaticallybrought into proper position relative to the ribbon "teeding mechanismwhen the platen carriage Frame is moved into its operating position.

I claim i. In combination, a ribbon spool, means for rotating saidspool, mechanism for reversing said rotating means, a movable member foractuating said reversing mechanism, a spring-controlled member foreffecting operative connection between said movable member and saidreversing mechanism, and a spring-controlled device for retaining saidspring-controlled member out of operative position, said device beingmovable by the ribbon on said spool for per mitting saidspring-controlled member to effect cooperative connection between saidmovable member and said reversing mechanism.

2. Ribbon mechanism tor typewriters comprising a rotary spindle, aribbon core movable into and out of position on said spindle, meansconnecting said core and spindle to cause them to rotate in unison withone another, a threaded. member for engaging said spindle to hold saidcore in place thereon, and a cover plate pivotally carried by saidthreaded member and having projections thereon arranged to engage saidcore when said threaded member is connected with said spindle.

3. Ribbon mechanism for typewriters comprising a pair of ribbon spools,a ratchet wheel ior each of said spools, dogs foroperating said ratchetwheels, levers for actuating said dogs, a movable bar on which saidlevers are pivoted, movable devices for operating said levers when thetypewriter is operated, and means controlled by the ribbon on saidspools and actuated by one or the other of said movable devices forshifting said bar to reverse the operation of said ribbon mechanism byshifting one of said levers into, and the other out or cooperativerelation with its respective movable device.

Ribbon reversing mechanism comprising a sliding bar, a bell crank leverhavin g one end thereof connected with said sliding bar, an actuator, acontact device pivot ally connected with said bell crank lever andmovable thereon into and out of the path of said actuator, a ribbonspool, operating mechanism for said ribbon spool carried by said bar andmovable therewith into and out of operative relation with said actuator,and ribbon control mechanism for moving said contact device on its pivotto cause said contact device to intercept the movement of said actuatorand operate said bell crank lever to shift said bar.

Ribbon reversing mechanism comprising a longitudinally movable bar, anactuator, a lever for shifting said bar, acontact device carried by saidlever, and means controlled by the ribbon for positioning said contactdevice in the path of said actuator to cause said actuator to operatesaid lever and shift said bar, the movement of said lever bringing saidcontact device beyond the path of movement of said actuator.

G. Ribbon reversing mechanism compris ing a longitudinally movable bar,a ribbon spool, ratchet mechanism for rotating said spool, a leverpivoted on said bar for operating said ratchet mechanism, an actuatorfor operating said lever, a bell crank lever for shifting said bar, acontact device carried by said lever and movable thereon into and out ofthe path of said actuator, and ribbon controlled mechanism forpermitting said contact device to move into the path of said actuatorwhen the ribbon is unwound from said spool so that said bell crank leverwill be operated by said actuator to shift said bar and simultaneouslydisconnect said ratchet mechanism from said spool and move the operatinglever for said ratchet mechanism out of cooperative relation with saidactuator.

7. A typewriter comprising a foldable platen carriage frame havingpivoted arms at opposite sides of the typewriter, a longitudinallymovable bar slidably mounted on said pivoted arms a ribbon spoolrotatably mounted on each of said arms, pawls mounted on each arm forrotating the ribbon spool carried thereby, levers mounted on said barfor operating said pawls, bell crank levers having pivots fixed to saidplaten carriage frame; actuators for each spool supported in- 10dependently of said platen carriage frame,

contact members o-n each of said bell crank levers, and ribboncontrolled means for moving said contact members into the path of saidactuators to shift said bar and effect a reversal of said ribbonmechanism.

In testimony whereof I have signed my name to thisspecificati'on on this7th da of August, A. D. 1920.

oTTo A.- i-ioiktaitsos'.

